Summary The Child Language Data Exchange System (CHILDES) Project seeks to broaden and deepen our scientific understanding of language development by providing new ways of analyzing real world face-to-face interactions. The computational tools that had been developed in the previous phases of the project constitute the primary methodological basis for new empirical research on the development of spontaneous use of a first language. This work has resulted in over 8000 published articles examining all aspects of language development, including word learning, sound learning, grammatical development, and communicative development. All of the programs and data sets are provided over the web without charge to researchers. The database that has been collected using these tools is now the largest spoken language database available anywhere. However, we can achieve still greater efficiency and analytic precision by building even more powerful computational tools. The next phase of this project will develop new techniques to support analytic methods in the study of language development. These methods include rapid computer-assisted transcription of interactions, diarization of daylong audio recordings made in the home, automatic analysis of morphological and syntactic structures, a simple user interface for searches, web-based support for collaborative commentary between research groups, construction of standard comparison group norms, and methods for moving data between different programs for alternative analyses. In addition, we will promote the use of the database and programs by constructing web-based tutorials, by improving the current user interface, and by conducting workshops and presentations at conferences.